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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 8th Nov 2019, 3:43 pm   #21
factory
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Default Re: Availability of TV valves for Nixie Clock.

Indeed completely obsolete, but combined with the recorder it was used for datalogging from other HP instruments in the 1960's, also the displayed time could be added to the print-out log.

David
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Old 8th Nov 2019, 10:35 pm   #22
MotorBikeLes
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Default Re: Availability of TV valves for Nixie Clock.

I know nothing about these things, but maybe these can help.
You probably all know of the 74141 used to drive the ZM1000 nixie in Grundig 6010 and 6011 colour TVs.
Later of course they went to 7 segment LEDs with the appropriate chips to drive them. This came to mind when I was working on my Advance frequency counter. That used 7 segment "nixie" tubes with a DS8880 driver chip. Not sure if that would be any use to you.
Les.
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Old 9th Nov 2019, 12:56 am   #23
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Default Re: Availability of TV valves for Nixie Clock.

Why not use ALL neon cold cathode valves?? BUT make the clock BCD display. I did this with LEDS years ago .
Add all the MSB's, then the LSB's while its counting!! Keeps the mind very agile.

Joe

p.s. I have boxes of CV2213,s !!!.
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Old 10th Nov 2019, 12:41 pm   #24
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Default Re: Availability of TV valves for Nixie Clock.

The 74141 is just logic gates configured to energise one output depending which specific combination of inputs is presented. And logic gates are just switches, so it's not an insurmountable problem.

For a display that changes once a second, you could just about get away with decoding the decimal digits using relays. To decode BCD, you would need up to five poles per binary digit. If you used twisted Johnson topology instead of BCD for your counters, you would need five flip-flops and relays per decimal digit (well, only three for the tens of minutes) but fewer poles on each (there are a lot of "don't care"s in the truth table).
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Old 10th Nov 2019, 1:19 pm   #25
TonyDuell
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Default Re: Availability of TV valves for Nixie Clock.

I suggested relays back in message #11.
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Old 11th Nov 2019, 12:47 pm   #26
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Default Re: Availability of TV valves for Nixie Clock.

Quote:
Originally Posted by julie_m View Post
The 74141 is just logic gates configured to energise one output depending which specific combination of inputs is presented. And logic gates are just switches, so it's not an insurmountable problem.
Actually it is not just that at all. For a TTL IC the '141 is quite amazing, the off state voltage is rated at 60V.

There are plenty of other BCD to decimal TTL decoder IC's, but nothing like this one suited to Nixie tubes.

If you look on ebay you will find that the original TI ones are more difficult to get, but it turns out the Russians cloned them, and as a result plenty of equivalents available.

One interesting thing (and I have yet to meet anyone who knows about this particular example) is what happens when a BCD to 7 segment decimal decoder chip is sent illegal values that correspond to A-F, what they do with that. Some types produce blanks which is handy, others produce a giberish display, but......there is one type that does something really interesting and I could tell you how I found this out, but its too long a story, the IC is a 9374.

On passing it values outside the range of 0 to 9, on the 7 segment display it produces the output H. E. L. P.... not kidding, here is the data sheet :

http://pdf.datasheetcatalog.com/data...ild/DM9374.pdf

I was once greeted with this message on a multi-digit seven segment display under some interesting circumstances.

Last edited by Argus25; 11th Nov 2019 at 1:06 pm. Reason: typo
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Old 11th Nov 2019, 11:34 pm   #27
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Default Re: Availability of TV valves for Nixie Clock.

Quote:
Originally Posted by woodchips View Post
Some thinking around and found a circuit where a pentode would act as a two stable state divider, halving the number of heaters at a stroke.

Still need a lot of pentodes, hence the quick search for the unwanted Uxx valves, but none. Can get EF80, EF91 from places, at 8+ each, which seemed a bit much.
Here you go, brand new B7G pentodes at 61 pence each!
Illustrative listing, there are plenty of others.
https://www.ebay.co.uk/itm/5PCS-6J2-...kAAOSwerdanVDs
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Old 25th Nov 2019, 11:01 am   #28
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Default Re: Availability of TV valves for Nixie Clock.

Just in case there is anyone still reading this thread, come across more information.

The book Industrial Electronics Handbook by Kretzmann has a chapter on counting. There is a full description of a divide by 10 counter using double triodes. Also a section on the E1T counting tubes, never seen one myself.

In fact if you ever come across this book in a shop definitely worth a few s, has some amazing things in it. Induction heating, motor control, control of lighting, welding, timing all from 1953, mine is the enlarged 3rd edition from 1959.

I am reading my way through my library, 1000 books on electromagnetism and similar. Why did these books become rubbish in the mid-1960s? Turned from trying to help and explain to 700 pages of differential equations?
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Old 25th Nov 2019, 1:37 pm   #29
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Default Re: Availability of TV valves for Nixie Clock.

I'm not sure what you mean, but if you want to really explain electromagnetism then differential equations are almost unavoidable.

The world of electronic engineering got an unpleasant jolt just after WW2. There was lots of EE innovation during the war, but at least in the UK it was seen that much of this came not from those trained in EE but those trained in physics. As a result it was decided that EE education had to contain much more science and maths, rather than just rules of thumb and handy formulas. In time this trickled through to the textbooks. However, even today it is still the case that many other countries have a far more rigourous engineering training than the UK.

I once submitted a paper to an instrumentation journal. It was a new method for calculating the behaviour of a particular type of probe tip, used for measuring dielectrics. One of the referees asked if the mathematics could be removed from the body of the paper and placed in an appendix - which would leave the paper consisting of an introduction and a conclusion, with nothing in between apart from a reference to the appendix. It was clear that he thought that mathematics had no place in an instrumentation research journal!
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Old 25th Nov 2019, 1:59 pm   #30
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Default Re: Availability of TV valves for Nixie Clock.

Quote:
Originally Posted by woodchips View Post
Just in case there is anyone still reading this thread, come across more information.

The book Industrial Electronics Handbook by Kretzmann has a chapter on counting. There is a full description of a divide by 10 counter using double triodes. Also a section on the E1T counting tubes, never seen one myself.
I have an old Racal counter that has 4 twin triodes (ECC8x) for each decade display, the digits are simple neon lamps in vertical columns . If I remember rightly there are 5 separate plug in decades in the unit. Dates from early 1950's I'm guessing.
I also have a few E1T counting tubes, they would make a very over the top analogue to digital replacement EM34! I cannot imagine a clock using these would be very readable.
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Old 25th Nov 2019, 2:38 pm   #31
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Default Re: Availability of TV valves for Nixie Clock.

Quote:
Originally Posted by G8HQP Dave View Post

I once submitted a paper to an instrumentation journal. It was a new method for calculating the behaviour of a particular type of probe tip, used for measuring dielectrics. One of the referees asked if the mathematics could be removed from the body of the paper and placed in an appendix
You may be aware that Stephen Hawking was warned that: "for every equation in his book, the readership would be halved" , he was only prepared to drop one equation.

I wrote a paper that contained > 30 equations. The irony was that to get to grips with the problem in a step-wise manner, it required most of them, unless you wanted pieces of a puzzle missing. Or maybe it was just me trying to connect all the links in a way I thought was solid.

I could never get it formally published though, every publisher who looked at it said it was difficult to "Monetize". So its an interesting lesson to learn.

I guess part of being a good scientific communicator is that you can do it successfully without the supporting equations, but you have them up your sleeve, if push comes to shove.
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Old 25th Nov 2019, 2:49 pm   #32
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Default Re: Availability of TV valves for Nixie Clock.

Quote:
Originally Posted by Argus25 View Post

You may be aware that Stephen Hawking was warned that: "for every equation in his book, the readership would be halved" , he was only prepared to drop one equation.

I guess part of being a good scientific communicator is that you can do it successfully without the supporting equations, but you have them up your sleeve, if push comes to shove.

Haha when I read this and a last few posts and this one in particular I suddenly thought of Professor Brian Cox and Helicopters flying around his head.


http://weebls-stuff.com/toons/profes...video-mrweebl/


Don't get me wrong I enjoy such things as the infinite monkey cage but as far as removing maths Brians got that off to a tee!


Cheers


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Old 27th Nov 2019, 3:25 am   #33
Bear2Biker
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Default Re: Availability of TV valves for Nixie Clock.

Hi there all,

So to get back to WoodChips idea of using valve technology to drive the Nixies, what about using those wire ended pencil tubes - Triode, Beam tetrode & Pentode in a small package, I got some 5840's & some Russian OTK 17's to play around with.

I had a quick look on ebay and there's a few suppliers mostly in the East but you can get a bundle of 10 for a few quid, types I've seen offered are as above and 5829, CV2288, CV2299, CV4503, DL73, EF70, 1J24B etc.

Filament requirements are quite low and vary from 1.4 to 6.3V 60 to 180mA and several types can cope with up to 200V on the anode/G3. Poking them up through the clock base in a pattern, or end on round the Nixies, or hide them altogether, there are a few suppliers of regulator tubes as well, you could have those on top and have them connected to the alarm feature all nice and Blue/Purple like.

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